fix(planner): note tooltip sizes to content (width max-content, cap 280)

Refines #594: a fixed width made short notes an oversized box and wrapped
long notes early. Use `width: max-content` capped at `max-width: 280` so
the tooltip hugs short notes on one line and grows to 280px before wrapping
long ones (instead of collapsing to the longest word, the pre-#593 bug).
Keeps the centered text.

Verified in local dev with both a short ("Zug zurück?") and a long note.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

apps/planner/app/components/PlannerMap.tsx

@@ -218,7 +218,7 @@ export function PlannerMap({ yjs, sessionId, onRouteRequest, highlightPosition,
           >
             {wp.note && (
               <Tooltip direction="top" offset={[0, -14]} opacity={0.95}>
-                <span style={{ width: 200, display: "inline-block", textAlign: "center", whiteSpace: "pre-wrap", overflowWrap: "break-word" }}>
+                <span style={{ width: "max-content", maxWidth: 280, display: "inline-block", textAlign: "center", whiteSpace: "pre-wrap", overflowWrap: "break-word" }}>
                   {wp.note.length > 120 ? wp.note.slice(0, 120) + "…" : wp.note}
                 </span>
               </Tooltip>